A New Technology Brings Smart Windows to Prominence

December 23, 2017 By The SOE Team

If you’re out to make some upgrades to your home or office in order to increase its energy efficiency, it’s likely your first move isn’t going to be to rip out all your windows and invest in newer, more efficient designs. Still, while getting all-new windows installed is an expensive efficiency upgrade, it’s also one of the most effective in terms of actual results.

This couldn’t be clearer for those living or working in a place with old or otherwise cheaply made windows. The difference in the amount of temperature-controlled air that escapes your home with inefficient windows as compared to newer models is almost unbelievable in some cases. The good news is you’re not the only one worried about energy-efficient windows.

Is a spray-on chemical the future for windows?

A newly engineered spray coating will make windows smarter than ever. With electrical currents, this chemical spray allows windows to stop a significant amount of heat and light from passing through, improving building comfort and saving energy spent on temperature adjustment.

According to the U.S. Department of Energy, about 4% of the $50 billion of U.S. energy consumption goes toward increased heating or cooling to compensate for heat transfer through windows. In addition, while the increased use of natural lighting has been linked to improved quality of life, sleep and workplace performance, sunlight can also heat your home or office like a greenhouse, forcing you to adjust the room temperature. It can also be distracting or uncomfortable if it is in your line of sight. Unfortunately, current window glazes and frames that can block much of this light are expensive and unreliable.

How the science works

The University of California at Berkeley lab Molecular Foundry recently published a study about its electrochromatic window that revolutionizes window capabilities. It created a heat-absorbent material out of nano-d, tin-based crystals that when given an electric shock absorb as much as 35% of heat-producing near-infrared radiation. Researchers then embedded these crystals into another chemically altered compound, which darkens the glass when exposed to electric currents. Together, these materials allow a user to control for heat and light passing through a window.

When a charge is applied, the nanocrystals absorb infrared heat. When a larger charge is applied, the crystals darken to block light. Combined, the compounds on the window can stop more than 50% of heat and 70% of visible light. The technology was developed with federal funds in conjunction with an Oakland, California, startup that specializes in smart windows. The coating is sprayed onto the inside of a glass pane. In a real-world setting, an additional coating would be needed to supply the necessary voltages.

More than a novelty product

Because it has performed well in both hot and cold temperatures, the developers say this spray film fills a tangible need and could result in reduced energy consumption and increased savings. It is the first product that attempts to address manipulating temperature and heat quantities as light passes through glass.

The research team is already in the process of bringing the product to the consumer market. Ultimately, the film needs to have a lower production cost before it can become a widespread commodity. Thus, the Berkeley lab is attempting to replace the tin oxide crystals with a much cheaper zinc-based material. For now, the findings are promising and present what may be the future for window insulation.